The invention is based on a piezoelectric positioning element, comprising a micrometer screw and a piezotranslator combined with it, the change in length of which, resulting from the application of voltage, causes a corresponding change in length at the spindle of the micrometer screw.
piezoelectric positioning elements of this type have already been disclosed by the present applicant. They are used wherever manual adjustment over several millimeters is to be done at the same time as an electrical control of position in the micrometer range. The coarse adjustment is accordingly done by the micrometer crew, while the fine adjustment is accomplished by the piezotranslator. These positioning elements have proved to be excellent for fine adjustment of mirrors, for mask positioning in the semiconductor industry, for positioning optical fibers, and in many other kinds of application, wherever the critical factor is not to measure the absolute position of a component but rather to position or adjust it highly accurately.
In previously known piezoelectric positioning elements, the piezotranslator has either been mounted on the front end of the measuring spindle, or has been kept small enough to be built into the spindle of the micrometer screw. In both cases, however, special micrometer screws must be used, having a non-rotating spindle. These screws are relatively large, and because of the special manufacture of the non-rotating spindle they are also considerably more expensive than the micrometer screws usually used.